Typically, terry weave is formed in three pick cycles, that is, with two partial beat ups and one full one. However, cycles involving four or more picks are often used, there always being at least one full beat up to the cycle. Three-pick-cycle terry is woven by placing individually two picks of weft into open sheds of ground and terry warp ends, and by means of the reed, moving those two picks of weft to a position parallel with, but separate from, the fell of the woven fabric. A third pick of weft is then inserted into a shed and all three are beat up to the fell of the fabric together by being slid between the tautly held ground warp ends. The terry warp ends are slackened prior to the moment of beat up and will be carried along with the three picks thereby forming loops on the top and bottom surfaces of the fabric. The distance or length of terry warp which separates the fell of the fabric and the position of placement of the first two picks of weft is a determining factor in the height of the resulting terry loops. It is desirable that this separating distance be easily andd accurately changed when necessary and positively retained while weaving any particular fabric construction. The positioning of the two or more picks of weft at a distance from the fell of the fabric will be termed in this disclosure a "partial beat up" as contrasted to the "full beat up" which takes place after insertion of the third and final pick of each three pick terry cycle.
In a loom for weaving terry-type fabric, a reed control mechanism must be used to vary the stroke of the reed to effect partial beat up of certain picks of weft and full beat up of other picks of weft. While numerous reed control mechanisms for terry-type looms are known in the art such as those disclosed in A. J. Herard et al, U.S. Pat. No. 2,082,888 issued June 8, 1937; G. Berg, U.S. Pat. No. 2,599,313 issued June 3, 1952; E. C. Nichols et al, U.S. Pat. No. 3,265,095 issued Aug. 9, 1966; Gotz et al, U.S. Pat. No. 3,339,589 issued Sept. 5, 1967; E. C. Nichols, U.S. Pat. No. 3,363,653 issued Jan. 16, 1968; J. D. Harkey, U.S. Pat. No. 3,434,504 issued Mar. 25, 1969; S. C. Tiernan, U.S. Pat. No. 3,467,146 issued Sept. 16, 1969; Volpe, U.S. Pat. No. 3,788,359 issued Jan. 29, 1974; Seifert, U.S. Pat. No. 3,889,719 issued June 17, 1975 and Robert, U.S. Pat. No. 3,939,876 issued Feb. 4, 1976, none of these references disclose a mechanically simple and economical reed control mechanism for reproducibly varying the stroke of the reed in a terry-type loom so as to effect partial beat up of certain picks and full beat up of other picks. In fact, in many conventional terry looms, relatively complex gearing or cam controlled linkage members are used to vary the stroke of the reed to implement the three-pick-terry cycle. One relatively simple reed control mechanism which is disclosed in Kuster et al, U.S. Pat. No. 3,822,726 issued July 9, 1974, utilizes a plurality of pneumatic or hydraulic cylinders to impart reciprocating motion to the reed in a loom. However, the Kuster reference does not provide a way for reproducibly varying the stroke of the reed so as to implement a terry-type weaving cycle comprising partial beat up of certain picks of weft and full beat-up of other picks of weft.
Accordingly, it is an object of the present invention to provide an economical and mechanically simple reed control mechanism which enables implementation of a terry-type weaving cycle comprising partial beat up of certain picks and full beat up of other picks. In addition, it is a further object of the present invention to provide a means for easily and accurately controlling the distance separating the partially beat up picks and the fell of the already woven fabric so as to control the pile height of the fabric.